Flexural properties of grooved perforation sandwich composites

Abstract

FANG方方 Hai( ): Ph D;Abstract: Selecting H-60 PVC foam, four-axis E-glass non-woven fabric and vinyl resin, a type of innovative reinforced sandwich composite as grooved perforation sandwich (GPS) were fabricated by VIMP. The interfacial structure between the face and core of the sandwich is innovative because of the acuminate grooves in both sides of foam core and the holes perforated along core's height. The fabrication results show that VIMP is a high-speed and cost-effective manufacturing method. The mechanical properties of the reinforced foam core were tested. The typical flexural failure modes of sandwich specimens were observed. The flexural stiffness and ultimate bearing capacity of sandwich were studied by ordinary sandwich beam theory and finite element method.

Characterization of the Si3N4/Si3N4 joints fabricated using particles modified braze

“…The problem could be alleviated through the addition of low CTE material, such as particles or fibers, in the filler alloy, and this method showed a remarkable effect in accommodating the residual stresses. Many kinds of particles were used as the incorporation in the brazed joint, such as carbon fiber [12][13][14], SiC [15][16][17][18][19], Si 3 N 4 [20], Al 2 O 3 [21,22], TiC [23], W [24] and TiB [25,26]. Our research group has introduced SiCp or Mo particles modified braze for joining Si 3 N 4 ceramic and obtained a high quality joint [27,28].…”

Improving the strength of brazed joints with in situ synthesized TiB whiskers

“…However, the quality of brazed joint is degraded by residual stress due to coefficient of thermal expansion (CTE) mismatch between metals and ceramics, and between brazing alloys and ceramics [2]. To solve this problem, low CTE materials (SiC [3][4][5], Al 2 O 3 [6], TiC [3,7,8]) have been added into brazing filler alloy. However, direct addition method has many intrinsic limitations.…”

Microstructural investigation of in situ TiB whiskers array reinforced ZrB2–SiC joint

“…In order to overcome this problem, some low CTE materials (such as SiC [7][8][9], Al 2 O 3 [10], TiC [11]) have been incorporated in the brazing alloy. However, direct addition has its intrinsic limitations, such as inhomogeneous distribution, poor wettability, etc.…”

“…However, direct addition has its intrinsic limitations, such as inhomogeneous distribution, poor wettability, etc. [10]. Recent studies [12,13] demonstrate that in situ synthesized TiBw with advantages of fine size, relative stability and compatibility, can relieve residual stress and increase shear strength of joints to some extent.…”